EP0418093A2 - Abrasif revêtu contenant un liant adhésif sensible à la pression en milieu aqueux - Google Patents

Abrasif revêtu contenant un liant adhésif sensible à la pression en milieu aqueux Download PDF

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Publication number
EP0418093A2
EP0418093A2 EP90310069A EP90310069A EP0418093A2 EP 0418093 A2 EP0418093 A2 EP 0418093A2 EP 90310069 A EP90310069 A EP 90310069A EP 90310069 A EP90310069 A EP 90310069A EP 0418093 A2 EP0418093 A2 EP 0418093A2
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EP
European Patent Office
Prior art keywords
coated abrasive
pressure
adhesive
sensitive adhesive
abrasive article
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP90310069A
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German (de)
English (en)
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EP0418093B1 (fr
EP0418093A3 (en
Inventor
C/O Minnesota Mining And Kopel Richard V.
Stephen J. C/O Minnesota Mining And Yoos
Donna W. C/O Minnesota Mining And Bange
Jens L. C/O Minnesota Mining And Jorgensen
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3M Co
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Minnesota Mining and Manufacturing Co
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Publication of EP0418093A3 publication Critical patent/EP0418093A3/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/21—Paper; Textile fabrics
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/22—Plastics; Metallised plastics
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

  • This invention relates to a coated abrasive product having a pressure-sensitive adhesive layer coatable from water.
  • coated abrasive products are mounted on a support pad, sometimes called a back-up pad, during use.
  • the purpose of the support pad is to provide the coated abrasive with the necessary foundation required for a particular abrading application.
  • the support pad will typically be durable, heat resistant, and rigid. If the coated abrasive article is to be employed for finishing contoured surfaces, the support pad will typically be soft and conformable.
  • One means for securing the coated abrasive article to the support pad calls for a pressure-sensitive adhesive.
  • the surface of the coated abrasive article not containing the abrasive grains will bear a layer of pressure-sensitive adhesive.
  • the pressure-sensitive adhesive of this layer must have sufficient adhesion to hold the coated abrasive article on the support pad for the intended abrading application.
  • the coated abrasive/support pad assembly rotates as many as 15,000 rpm. If the pressure-sensitive adhesive does not have sufficient adhesion, the coated abrasive article can fly off the support pad at high rotation speeds, thereby resulting in excessive downtime.
  • U.S. Patent No. 2,286,208 discloses coated abrasive products having several different types of solvent-based pressure-sensitive adhesives. These pressure-sensitive adhesives include ethyl cellulose adhesives, alkyd resins, rubber-based adhesives, and rosin-based adhesives.
  • U.S. Patent No. 2,544,940 discloses a polishing pad for use with loose abrasive grain.
  • the polishing pad is adhered to a support pad by a natural, synthetic, or chlorinated rubber.
  • U.S. Patent No. 2,888,785 discloses a coated abrasive that is adhered to a support pad by a rubber-based pressure-sensitive adhesive.
  • U.S. Patent No. 3,849,949 discloses a convolutely wound roll of coated abrasives, each of which contains a pressure-sensitive adhesive coating on the non-abrasive side.
  • the pressure-sensitive adhesive is a water-based acrylate adhesive.
  • U.S. Patent No. 3,875,703 discloses a coated abrasive disc that is adhered to a support pad by a rubber-based latex adhesive.
  • pressure-sensitive adhesives have been coated from organic solvent solutions onto the non-abrasive side of the coated abrasive article with excellent results.
  • the coated abrasive industry should eliminate all organic solvents from their coating operations. Accordingly, it would be desirable to replace pressure-sensitive adhesives coated from organic solvents with pressure-sensitive adhesives coated from water.
  • pressure-sensitive adhesives coated from water do not exhibit sufficient adhesion to consistently prevent abrasive discs from flying off support pads. Accordingly, for some products, the coated abrasive industry is forced to rely on pressure-sensitive adhesives coated from organic solvents in order to obtain the required adhesive properties.
  • This invention relates to a coated abrasive article having a backing bearing abrasive grains on one major surface thereof and a pressure-sensitive adhesive, coatable from water, on the other major surface thereof.
  • the pressure-sensitive adhesive can be used to secure the coated abrasive article to a support pad or back-up pad.
  • the support pad provides the coated abrasive article with the necessary foundation during abrading operations.
  • the pressure-sensitive adhesive comprises a water-emulsifiable, tacky adhesive formed from a copolymer of vinyl acetate and at least one terminally unsaturated vinyl monomer.
  • the pressure-sensitive adhesive comprises (a) a first component comprising a water-emulsifiable, tacky adhesive selected from the group consisting of (i) rubber-based adhesives, (ii) silicone-based adhesives, (iii) polyvinyl acetate-based adhesives, and (iv) copolymer formed from vinyl acetate and at least one terminally unsaturated vinyl monomer; and (b) a second component comprising a water-emulsifiable acrylic adhesive.
  • a first component comprising a water-emulsifiable, tacky adhesive selected from the group consisting of (i) rubber-based adhesives, (ii) silicone-based adhesives, (iii) polyvinyl acetate-based adhesives, and (iv) copolymer formed from vinyl acetate and at least one terminally unsaturated vinyl monomer
  • a second component comprising a water-emulsifiable acrylic adhesive.
  • Either of the foregoing embodiments provide a high-performance pressure-sensitive adhesive that can be successfully employed with coated abrasive articles.
  • the aforementioned pressure-sensitive adhesives can adequately secure the coated abrasive article to a support pad even at high rotation speeds and at high grinding pressures.
  • Previously known pressure-sensitive adhesives for coated abrasives that were coated from water were unable to provide this property.
  • the aforementioned pressure-sensitive adhesives provide sufficient adhesive strength to secure coated abrasive articles having a cloth backing to a support pad. Because cloth-backed coated abrasive products usually have more mass associated with them than do paper-backed coated abrasive products of lighter weight, pressure-sensitive adhesives for cloth-backed products must have adhesive properties superior to those of pressure-sensitive adhesives for paper-backed products of lighter weight. Previously known pressure-sensitive adhesives coated from water for cloth-backed coated abrasive articles did not exhibit sufficient adhesive properties to assure that the coated abrasive article would not separate from the support pad during use.
  • coated abrasive article 10 comprises a backing 12 bearing on one major surface thereof a layer of abrasive grains 14.
  • Backing 12 is preferably formed from paper, cloth, polymeric film, vulcanized fiber, non-woven material, woven material, or combinations thereof.
  • the backing can be treated or remain untreated.
  • backing 12 bears a treatment or coating commonly referred to as a presize.
  • Abrasive grains 14 are preferably made of material selected from the group consisting of aluminum oxide, ceramic aluminum oxide, alumina zirconia, silicon carbide, flint, garnet, diamond, and mixtures thereof. Other commonly known abrasive grains can also be used.
  • abrasive grains 14 are secured to backing 12 by a first adhesive layer or binder layer 18, commonly referred to as the "make coat”.
  • a first adhesive layer or binder layer 18 can be applied over the abrasive grains.
  • Layer 20 is commonly referred to as the "size coat”.
  • Layer 20 provides additional reinforcement for abrasive grains 14.
  • Common adhesives and binders for layers 18 and 20 include phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, glue, starch, epoxy resins, acrylate resins, latices, and combinations and mixtures thereof.
  • coated abrasive article need not have both a make coat and size coat; instead, the abrasive grains can be mixed with an adhesive or binder and then applied to the backing as a slurry. The abrasive grains are then secured to the backing by a single adhesive or binder layer.
  • a layer of pressure-sensitive adhesive suitable for use in this invention 22 is borne on the major surface of backing 12 not bearing abrasive grains 14.
  • coated abrasive article 10 may contain an optional liner 24 over layer 22 of pressure-sensitive adhesive.
  • Liner 24 typically consists of paper or polymeric film having a coating of a low adhesion material that is in direct contact with layer 22 of pressure-sensitive adhesive. Examples of such low adhesion materials are polyethylene, silicones, and high molecular weight waxy materials.
  • the pressure-sensitive adhesive of layer 22 must meet at least four major criteria. These criteria are tack, peel strength, removal, and shear strength.
  • Tack is the ability of an adhesive to adhere quickly to a surface; with respect to the present invention, it is a measure of the initial contact between the coated abrasive article and the support pad.
  • the pressure-sensitive adhesive must have sufficient tack over a wide range of temperatures and humidities, because coated abrasive articles are used throughout the world in both indoor and outdoor environments. In other words, the pressure-sensitive adhesive of layer 22 must be tacky.
  • tacky means having a sticky nature or immediate adhesion on contact with a substrate. Some adhesives are inherently tacky while others can be rendered tacky by addition of a tackifier. The term “tacky” is intended to refer to both inherently tacky adhesives and adhesive compositions that include an added tackifier.
  • Peel strength is a measure of the ability of a pressure-sensitive adhesive to resist removal by being peeled away from a surface, and is also a measure of how well the pressure-sensitive adhesive bonds to a surface, e.g., a support pad.
  • Removal is a measure of the ability of the coated abrasive article to be cleanly removed from the support pad. Peel strength and removal are competing properties. Pressure-sensitive adhesives useful in this invention must have sufficiently high peel strength so that the coated abrasive article will not come off of the support pad during use. However, if the peel strength is too high, the operator cannot remove or cleanly remove the coated abrasive article from the support pad when the abrasive grains have been consumed without tearing the backing. After the coated abrasive article is worn, it is discarded, but the support pad is used many times over. If the peel strength of the pressure-sensitive adhesive is too great, residual pressure-sensitive adhesive may remain on the surface of the support pad when the coated abrasive article is removed.
  • Shear strength is a measure of the ability of a pressure-sensitive adhesive to cause the article it is bonding to remain in its initial position when shear forces are applied. Shear forces are applied to the coated abrasive article/support pad assembly from both rotating and grinding. If the pressure-sensitive adhesive does not have sufficient shear strength, the coated abrasive article will fly off the support pad during use and cause inconvenience to the operator. Both the mass and the Young,s modulus for a coated abrasive article and a support pad are different. Because of this disparity, the torque caused by the rotating and the grinding forces each affect the coated abrasive article and support pad differently. These forces can lead to the separation of the coated abrasive article from the support pad.
  • the pressure-sensitive adhesive must have sufficient shear strength to resist the separation of the coated abrasive article from the support pad caused by these forces. Grinding also results in generation of heat. In general, as the temperature increases, the shear strength of pressure-sensitive adhesives decreases. Because the temperature that the pressure-sensitive adhesive may experience can exceed 100°C under severe grinding conditions, the pressure-sensitive adhesive should have sufficient shear strength under elevated temperatures to secure the coated abrasive to the support pad.
  • the coating weight of the pressure-sensitive adhesive the higher will be the tack and peel strength and the lower will be the shear strength thereof.
  • the coating weight of the adhesive layer must be optimized for each coated abrasive article product and grade.
  • the pressure-sensitive adhesive comprises a water-emulsifiable, tacky adhesive formed from a copolymer of vinyl acetate and at least one terminally unsaturated vinyl monomer.
  • copolymer means a composite polymer prepared by the polymerization of a mixture of two or more monomers, or of a monomer and polymer of low molecular weight.
  • An example of a pressure-sensitive adhesive of this type has the trade designation "Flexcryl 1625" and is commercially available from Air Products Company.
  • terminally unsaturated vinyl monomers include isooctyl acrylate, ethyl acrylate, isobutyl acrylate, isononyl acrylate, 2-ethyl hexyl acrylate, and methyl methacrylate.
  • the emulsifier for this adhesive can be anionic, non-ionic, or combinations of both, depending on the particular system. Anionic emulsifiers are preferred because they tend to produce more stable emulsions.
  • An example of an anionic emulsifier has the trade designation "Triton X-200" and an example of a non-ionic emulsifier has the trade designation "Triton X-100", both of which are commercially available from Rohm and Haas Company.
  • the pressure-sensitive adhesive comprises (a) a first component comprising a water-emulsifiable, tacky adhesive selected from the group consisting of (i) rubber-based adhesives, (ii) silicone-based adhesives, (iii) polyvinyl acetate-based adhesives, and (iv) a copolymer formed from vinyl acetate and at least one terminally unsaturated vinyl monomer and (b) a second component comprising a water-emulsifiable acrylic adhesive.
  • a first component comprising a water-emulsifiable, tacky adhesive selected from the group consisting of (i) rubber-based adhesives, (ii) silicone-based adhesives, (iii) polyvinyl acetate-based adhesives, and (iv) a copolymer formed from vinyl acetate and at least one terminally unsaturated vinyl monomer and (b) a second component comprising a water-emulsifiable acrylic adhesive.
  • rubber-based adhesives suitable for the first component include thermoplastic elastomers, such as, for example, styrene-butadiene-styrene, styrene-isoprene-styrene, and styrene-ethylene/butylene-­styrene.
  • thermoplastic elastomers such as, for example, styrene-butadiene-styrene, styrene-isoprene-styrene, and styrene-ethylene/butylene-­styrene.
  • Representative examples of commercially available adhesives include the styrene-isoprene-styrene elastomer "Kraton 1107" and the styrene-ethylene/butylene-­styrene elastomer "Kraton 1657", both of which are available from Shell Chemical Company.
  • silicone-based adhesives include silicone elasto
  • silicone elastomers or gums are typically provided as solvent solutions of elastomer or gum and MQ resin, such as, for example, that described in U.S. Patent No. 4,460,371, incorporated herein by reference (especially column 5, line 47 through column 7, line 26, thereof).
  • Representative examples of silicone elastomers have the trade designation "Silgrip PSA 595", “Silgrip PSA 596”, and “Silgrip PSA 6574", all of which are available from General Electric Company.
  • the adhesives of the first component can be tackified by (a) incorporation of a tackifying agent, (b) appropriate modification of the structure of the adhesive molecule, or (c) a combination of both approaches.
  • Tackifiers that have been found to be suitable for tackifying the pressure-sensitive adhesive of the first component include low molecular weight hydrocarbon resins, and alpha- and beta-pinene based resins.
  • tackifiers include the resins having the trademarks "Regalrez 1018" and “Regalrez 1078", both of which are available from Hercules Incorporated, "Exxon ECR 111", “Exxon ECR 327”, and “Exxon ECR 328”, all of which are available from Exxon Corporation, and "Wingtack Plus", which is available from Firestone Tire and Rubber Company.
  • the ratio of tackifier to adhesive in the first component preferably ranges from about 0.5:1.0 to about 1.5:1.0.
  • a preferred method of preparing the rubber-based, silicone-based, and polyvinyl acetate-based adhesives for the first component of the second embodiment is described below.
  • a solution containing the emulsifiable, tacky adhesive is prepared by combining the following ingredients in the amounts indicated:
  • the solvent used to dissolve the adhesive of the first component have low polarity and low hydrogen bonding. As polarity of the solvent increases, it tends to mix with the water utilized to prepare an aqueous emulsion and emulsion stability may be impaired.
  • the solvent is preferably selected from the group consisting of toluene, xylene, naphtha, heptane, methylene chloride, and mixtures thereof.
  • the resulting solution can then be converted into an emulsion by the addition of from about 10 to 70 parts by weight water and from about 0.25 to about 10 parts by weight surfactant. It is preferred that the water used to form the emulsion be deionized, because deionized water provides greater emulsion stability. A portion of the water, preferably no more than about 25% by weight, can be replaced by alcohol, e.g., monohydric alcohol having 1 to 6 carbon atoms. It is necessary to convert the solution containing the adhesive to an emulsion so that it can be readily combined with the second component, which is typically provided in the form of an emulsion.
  • alcohol e.g., monohydric alcohol having 1 to 6 carbon atoms
  • the solution is premixed with non-ionic surfactant
  • the water is premixed with anionic surfactant before the solution is combined with the water to form the emulsion.
  • non-ionic surfactant for each 100 parts by weight adhesive solution, about 0.55 part by weight non-ionic surfactant is typically added to the adhesive solution, and for each 20 parts by weight water, 0.28 part by weight anionic surfactant is typically added to the water.
  • a small amount of anionic surfactant can be used to replace a larger amount non-ionic surfactant, with the result that the total amount of surfactant needed is reduced. Up to 50% by weight of non-ionic surfactant can be replaced by a lesser percentage by weight of anionic surfactant. For example, if one part by weight of non-ionic surfactant were normally required, 0.5 part by weight of non-ionic surfactant could be replaced by less than 0.5 part by weight of anionic surfactant.
  • a non-ionic surfactant suitable for the present invention has the trade designation "Triton X-100" and an anionic surfactant suitable for the present invention has the tradename "Triton X-200", both of which are commercially available from Rohm and Haas Company. The amount of surfactant must not be so high that it will adversely affect the tack, peel strength, and shear strength of the pressure-sensitive adhesive.
  • the second component comprises a water-emulsifiable acrylic adhesive.
  • acrylic adhesives suitable for this invention are disclosed in Silver, U.S. Patent No. 3,922,464, incorporated herein by reference (see column 3, line 28 through column 4, line 2 of U.S. Patent No. 3,922,464).
  • monomers that can be used to make acrylic adhesives include isooctyl acrylate, 2-ethyl hexyl acrylate, methyl methacrylate, and isononyl acrylate.
  • the acrylic adhesives can be modified with various components such as N-tert-octylacrylamide, N-tert-butylacrylamide, N-tert-amylacrylamide, N-isopropylacrylamide, carboxylic acids, acrylates, methacrylates, and others as are known in the art.
  • the acrylic-based monomer is dispersed in water with an appropriate emulsifier.
  • This dispersion may contain modifiers, such as, for example, anti-oxidants, inorganic fillers, thixotropic agents, stabilizers, and dyes. Examples of such additives can be found in U.S. Patent No. 4,835,217, incorporated hereinafter by reference (see especially col. 7, line 25 through col. 8, line 4 of U.S. Patent No. 4,835,217).
  • the monomer, and optional modifiers, if any are then polymerized.
  • the water used to form the emulsion be deionized, as deionized water provides greater emulsion stability.
  • the emulsifier can be anionic, non-ionic, or combinations of both, although anionic is preferred because it tends to provide better emulsion stability.
  • An example of an anionic emulsifier has the trade designation "Triton X-200" and an example of a non-ionic emulsifier has the trade designation "Triton X-100", both of which are commercially available from Rohm & Haas Company.
  • the emulsifier for the second component be a vinyl-unsaturated polymerizable monomer.
  • This monomer can then copolymerize with the other acrylic monomer of the second component.
  • This monomer must have both hydrophobic and hydrophilic moieties, contain at least 5 but not more than 40 carbon atoms, and be water dispersible.
  • the monomer comprises a monovalent salt of a styrene sulfonate such as that disclosed in U.S. Patent No. 4,835,217, previously incorporated herein by reference (see column 4, lines 54 to 68 and column 5, lines 1 to 15 of U.S. Patent No. 4,835,217).
  • the emulsifier can also be formed from a vinyl-unsaturated polymerizable monomer and a zwitterion monomer.
  • the vinyl-unsaturated monomer must have both hydrophobic and hydrophilic moieties, contain at least 5 but not more than 40 carbon atoms, and be water dispersible.
  • the zwitterion monomer has a free radically polymerizable unsaturated group. This copolymer is described more in detail in U.S. Patent No. 3,922,464.
  • the aqueous emulsion of the first component is then combined with the aqueous emulsion of the second component to form the pressure-sensitive adhesive of the second embodiment of the invention.
  • the ration of first component to second component in the pressure-sensitive adhesive of the second embodiment based on weight, preferably ranges from about 5:1 to about 1:5, and more preferably ranges from 1:1 to 1:5. Ratio outside of these ranges can also be used to prepare useful pressure-sensitive adhesives for coated abrasive articles.
  • Some water emulsifiable acrylic adhesives are shear sensitive. If the adhesive is shear sensitive, as in the case of the acrylic adhesive described in U.S. Patent No. 4,835,217, care must be taken during processing to avoid coagulation. For example, if the water emulsifiable acrylic adhesive is mixed with other adhesives, the duration of mixing and the speed of the mixing apparatus should not be excessive in order to avoid coagulation. The duration of mixing is typically less than 60 minutes, preferably less than 20 minutes.
  • the pressure-sensitive adhesive After the pressure-sensitive adhesive is prepared, it is coated on the major surface of the coated abrasive article not bearing abrasive grains. During the coating process, the adhesive is preferably not pumped to the coating station; instead, it is preferred that the adhesive be gravity fed to avoid coagulation. This coating can be applied by any method typically used in the art, such as, for example, roll coating, knife coating, spraying, or die coating. After the layer of pressure-sensitive adhesive is coated, the resulting coated abrasive article is heated from about three minutes to about 10 hours at 25°C to 80°C to dry the adhesive.
  • a smoothing blanket should be employed to smooth out the adhesive to prevent the coating from developing a ridge-like pattern. If a ridge-like pattern were to form, the adhesive to the support pad would be poor.
  • the smoothing blanket can be formed from a polymeric film, such as polyester film, having a low adhesion coating, such as a silicone material, on the side that contacts the adhesive.
  • the length of the smoothing blanket is determined by the width of the backing and the speed of the coater. The smoothing blanket should not be excessively long. If it were too long, it would act as a knife and stick to the adhesive. Additionally, there would be an undesirable build-up of frictional force between the adhesive coated web and the smoothing blanket.
  • the coating weight of the adhesive has a significant effect on the drying time, i.e., the lower the coating weight, the shorter the drying time. It is preferred that the adhesive be dried at between 25°C and 35°C for approximately 60 minutes to 120 minutes to allow the adhesive to penetrate into the backing. Then the adhesive is preferably dried for 30 minutes to 150 minutes at between 30°C to 35°C. If the temperature is too high, e.g., greater than 60°C, blistering may occur and the top surface of the adhesive will be dried, while the back of the adhesive will not be dried.
  • the weight of the adhesive should be sufficiently high to provide sufficient adhesive strength to hold the coated abrasive to the support pad under high rotational speeds, but it should not be so high that the coated abrasive cannot be readily removed from the support pad once the coated abrasive needs to be replaced.
  • the coated abrasive article can be converted into a wide variety of different forms such as discs, sheets, rolls, and cones.
  • the major surface of the coated abrasive article not bearing abrasive grains may be primed or coated with another material prior to the application of the layer of pressure-sensitive adhesive. This priming or additional coating enhances the adhesion between layer 22 of pressure-sensitive adhesive and backing 12.
  • the blend of the two components in the second embodiment provides an adhesive that exhibits the necessary properties for a coated abrasive.
  • the first component acts to provide good shear strength and water resistance.
  • the second component acts to provide good peel strength over a wide temperature range.
  • the pressure-sensitive adhesive of this invention may also include such additives as anti-oxidants, inorganic fillers, thixotropic agents, stabilizers, and dyes.
  • additives as anti-oxidants, inorganic fillers, thixotropic agents, stabilizers, and dyes. Examples of such additives can be found in U.S. Patent No. 4,835,217, incorporated hereinafter by reference (see column 7, lines 25 to 68 and column 8, lines 1 to 4 of that patent).
  • the Wet Test simulated the effect of water on the pressure-sensitive adhesive during sanding or grinding operations.
  • Each coated abrasive sample was converted to a 7.6 cm diameter disc. In water, the disc was pressed against a 7.6 cm diameter rubber support pad.
  • the coated abrasive sample/support pad assembly was used to sand a gelcoat plastic for two minutes. The initial and final adhesion between the coated abrasive sample and the support pad was noted.
  • a rating system was used in which a rating of 1 meant that there was no adhesion between the pressure-sensitive adhesive and the support pad, a rating of 2 meant that there was poor adhesion between the pressure-sensitive adhesive and the support pad, a rating of 3 meant that there was adequate adhesion between the pressure-sensitive adhesive and the support pad, and a rating of 4 meant that there was good adhesion between the pressure-sensitive adhesive and the support pad.
  • This test simulated dry sanding conditions carried out with a random orbital sander.
  • the purpose of the test was to determine if any pressure-sensitive adhesive transferred to the support pad after the coated abrasive article was removed from it.
  • the coated abrasive article from each example was converted to a 12.7 cm diameter disc and was pressed against a 12.7 cm diameter vinyl support pad attached to a random orbital sander.
  • the coated abrasive article was used to sand an edge (approximately 0.7 cm thick) of a plastic/fiberglass composite panel for approximately two minutes. After the sanding, the coated abrasive article was removed and the amount of adhesive transfer to the support pad was determined.
  • a rating system was developed in which a rating of 1 meant that there was no initial adhesion between the layer of pressure-sensitive adhesive and the support pad.
  • a rating of 2 meant that there was good adhesion between the layer of pressure-sensitive adhesive and the support pad, but when the coated abrasive article was removed, an undesirable amount of adhesive remained on the support pad.
  • a rating of 3 meant that there was good adhesion between the layer of pressure-sensitive adhesive and the support pad, but when the coated abrasive article was removed, a small amount of adhesive remained on the support pad.
  • a rating of 4 meant that there was good adhesion between the layer of pressure-sensitive adhesive and the support pad, and when the coated abrasive article was removed, no visible adhesive remained on the support pad.
  • the coated abrasive article was converted to a 7.6 cm diameter disc and pressed against a 7.6 cm butyl rubber support pad that was attached to an air grinder.
  • the coated abrasive disc/support pad assembly rotated at 15,000 rpm.
  • the coated abrasive disc was used to grind the welds and corners of cold-rolled steel for one minute. This test was considered to be a severe grinding test and measured how well the coated abrasive disc remained on the support pad during grinding operations.
  • a rating system was developed in which a rating of 0 meant that the coated abrasive disc flew off, indicating a complete failure, a rating of 1 meant that adhesion between the coated abrasive disc and the support pad was poor, a rating of 2 meant that adhesion between the coated abrasive disc and the support pad was fair and the disc barely passed the test, a rating of 3 meant that there was good adhesion between the coated abrasive disc and the support pad, a rating of 4 meant that there was excellent adhesion between the coated abrasive disc and the support pad, and a rating of 5 meant that there was superb adhesion between the coated abrasive disc and the support pad.
  • This test provided an indication of relative shear strength of different adhesives.
  • Each coated abrasive article from each example was converted to strips 2.54 cm wide.
  • the adhesive bearing side of each strip of each coated abrasive article of each example was pressed onto a vinyl backing by means of a 2.0 kg roller.
  • a vinyl backing was used to simulate the support pad.
  • An "Instron" testing apparatus was used to pull the strip of each example apart from the vinyl backing at a rate of 13 cm/min.
  • the angle between the strip of each example and the vinyl backing throughout the test was maintained close to 0°.
  • the peak load was measured. In general, the higher the lap shear value, the greater is the shear strength.
  • This test provided an indication of how well the layer of pressure-sensitive adhesive adheres to the backing of the coated abrasive article.
  • the coated abrasive article of each example was converted to strips 2.54 cm wide.
  • An "Instron" testing apparatus was employed to pull the strip of #396 tape apart from the strip of each example at a rate of 51 cm/min. The angle between the strips of #396 tape and each coated abrasive article throughout the test was maintained near 90°.
  • the force to separate the #396 adhesive tape from the layer of pressure-sensitive adhesive of each coated abrasive article was measured. In this type of test, a failure occurred when the #396 adhesive tape removed the pressure-sensitive adhesive from the backing of the coated abrasive article. The force and failure mode was then recorded.
  • This test measured the relative peel strengths of pressure-sensitive adhesives of the coated abrasive articles.
  • the coated abrasive article of each example was converted to strips 2.5 cm wide.
  • a coated abrasive strip was then pressed against a 2.54 cm wide vinyl strip by means of a 2.0 kg roller.
  • the vinyl strip simulated a support pad.
  • An "Instron" testing apparatus was employed to pull the vinyl strip apart from the strip of each example at a rate of 51 cm/min.
  • the angle between the strips of vinyl and each coated abrasive article throughout the test was maintained near 90°.
  • the average peak force required to separate the vinyl strip from the layer of pressure-sensitive adhesive of each coated abrasive article was measured and recorded.
  • a rating system was developed in which a rating of 1 meant that there was no adhesion between the coated abrasive disc and the support pad, a rating of 2 meant that adhesion between the coated abrasive disc and the support pad was poor, a rating of 3 meant that adhesion between the coated abrasive disc and the support pad was fair, a rating of 4 meant that adhesion between the coated abrasive disc and the support pad was good, a rating of 5 meant that adhesion between the coated abrasive disc and the support pad was very good, and a rating of 6 meant that adhesion between the coated abrasive disc and the support pad was excellent.
  • a solvent-based pressure-sensitive adhesive was coated onto the major surface of the backing not bearing abrasive grains of a grade 320 "Tri-M-ite" "Wetordry” paper Type W2 commercially available from the Minnesota Mining and Manufacturing Company, St. Paul, Minnesota.
  • the coating was applied by means of a knife coater, and the adhesive was gravity fed into the knife coater.
  • the adhesive consisted essentially of isooctyl acrylate:acrylic acid copolymer.
  • the coated abrasive article was subjected to the Wet Test and the test results are set forth in Table I.
  • the coated abrasive article of this example was prepared and tested in the same manner as that of Comparative Example A, except that a different adhesive was used.
  • the adhesive was a rubber-based, water-emulsifiable, tacky adhesive prepared according to Example 1 of U.S. Patent No. 4,835,217.
  • the coated abrasive article was subjected to the Wet Test and the test results are set forth in Table I.
  • the coated abrasive article of this example was prepared and tested in the same manner as that of Comparative Example A, except that a different adhesive was used.
  • the adhesive was a blend of a water-emulsifiable acrylic adhesive (3 parts) with a rubber-based, water-emulsifiable tacky adhesive (1 part).
  • the water-emulsifiable acrylic adhesive was prepared according to U.S. Patent No. 4,835,217 (see column 10, U.S. Patent No. 4,835,217, "Preparation of Second Component".)
  • the rubber-based, water-emulsifiable adhesive was the same adhesive as that used in Comparative Example B.
  • the coated abrasive article was subjected to the Wet Test and the test results are set forth in Table I.
  • Table I Example Initial adhesion Final adhesion Comparative A 2 1 (The disc came off the support pad during sanding.) Comparative B 1 The disc could not be used for sanding. 1 4 4 4
  • Examples 2 to 8 compare the results obtained from the use of various ratios of the water-emulsifiable, acrylic adhesive to the water-emulsifiable, rubber-based adhesive.
  • the coated abrasive articles were prepared in the same manner as that of Example 1, except for the differing ratios of adhesive components.
  • the coated abrasive articles from the examples were evaluated under the Wet Test and the Random Orbital Test.
  • the adhesive component ratios and results are set forth in Table II.
  • Example acrylic rubber Wet test Random orbital test 2 1 1 2 3 3 2 1 2 3 1* 3 1 4 4 4 4 1 4 4 5 5 1 4 4 6 1 2 1 2 7 1 3 1 2 8 1 4 3 1 *
  • Example 1 is included in Table II in order to compare the effectiveness of the coated abrasive article therein with those of Examples 2-8.
  • the coated abrasive article of Comparative Example C was a grade 36 "Three-M-ite" Resin Bond Cloth, X weight PSA, pressure-sensitive adhesive-coated abrasive commercially available from the Minnesota Mining and Manufacturing Company, St. Paul, Minnesota.
  • the pressure-sensitive adhesive that had been previously coated on the surface of the backing not bearing abrasive grains of the coated abrasive was a rubber-based adhesive coated from a solvent.
  • the cloth backing was primed prior to application of the adhesive.
  • a water-emulsifiable acrylic-based pressure-sensitive adhesive was coated on the surface of the backing not bearing abrasive of a grade 36 "Three-M-ite" Resin Bond Cloth, X weight, coated abrasive article commercially available from the Minnesota Mining and Manufacturing Company, St. Paul, Minnesota.
  • the coating weight was 162 g/m2. This particular adhesive was shear sensitive; therefore the adhesive could not be pumped.
  • the adhesive was first poured into a coating trough. The adhesive was then applied with a roll coater, and immediately after application, a smoothing blanket smoothed out the adhesive across the web.
  • the smoothing blanket was a polyester film bearing a low surface energy coating made of silicone on the side that contacted the adhesive.
  • This coated abrasive article differed from the coated abrasive article of Comparative Example C in that it did not bear the rubber-based adhesive, coated from a solvent, that was described in that example.
  • the water-emulsifiable acrylic-based adhesive was prepared according to U.S. Patent No. 4,835,217 (see column 10, U.S. Patent No. 4,835,217, "Preparation of Second Component"). After the adhesive had been coated, the adhesive was dried in an oven at 25°C for 25 to 30 minutes and at 50°C for 40 minutes.
  • the coated abrasive article of this example was prepared in the same manner as that of Comparative Example D, except that a different adhesive was employed.
  • the adhesive consisted of a water-emulsifiable, tacky copolymer of vinyl acetate and at least one terminally unsaturated vinyl monomer.
  • the adhesive had the trade designation "Flexcryl 1625", and was commercially available from Air Products Company. It is believed that "Flexcryl 1625" adhesive is an anionically stabilized blend of ethylhexyl acrylate (77 percent by weight), methylmethacrylate (15 percent by weight), and vinyl acetate (8 percent by weight). The adhesive was dried at 30°C for 7 minutes and at 50°C for 40 minutes.
  • the coated abrasive article of this example was prepared in the same manner as that of Example 9, except that the adhesive consisted of a 75% by weight "Flexcryl 1625" adhesive and 25% by weight of an acrylic adhesive such as that described in Comparative Example D.
  • the coated abrasive article of this example was prepared in the same manner as that of Example 10, except that the ratio, based on weight, between the two adhesives was 60% by weight "Flexcryl 1625" adhesive and 40% by weight acrylic adhesive.
  • the coated abrasive article of this example was prepared in the same manner as that of Example 10, except that the ratio, based on weight, between the two adhesives was 50% by weight "Flexcryl 1625" adhesive and 50% by weight acrylic adhesive.
  • the coated abrasive article of this example was prepared in the same manner as that of Example 10, except that the ratio, based on weight, between the two adhesives was 40% by weight "Flexcryl 1625" adhesive and 60% by weight acrylic adhesive.
  • the coated abrasive article of this example was prepared in the same manner as that of Example 10, except that the ratio, based on weight, between the two adhesives was 25% by weight "Flexcryl 1625" adhesive and 75% by weight acrylic adhesive.
  • Table III Example Adhesive coating weight (g/mm2) Fly-Off Test Lap Shear Test (kg) Comparative C 1.5 4 9.76 Comparative D 2.4 2.25 17.3 9 2.6 5 14.5 10 2.9 4.5 17.3 11 1.8 3.25 18.2 12 2.5 3 19.5 13 2.2 2.25 20.0 14 2.2 4 15.9 Table IV

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Adhesive Tapes (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
EP90310069A 1989-09-15 1990-09-14 Abrasif revêtu contenant un liant adhésif sensible à la pression en milieu aqueux Expired - Lifetime EP0418093B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US40796789A 1989-09-15 1989-09-15
US407967 1989-09-15

Publications (3)

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EP0418093A2 true EP0418093A2 (fr) 1991-03-20
EP0418093A3 EP0418093A3 (en) 1992-04-01
EP0418093B1 EP0418093B1 (fr) 1995-01-25

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ID=23614300

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EP90310069A Expired - Lifetime EP0418093B1 (fr) 1989-09-15 1990-09-14 Abrasif revêtu contenant un liant adhésif sensible à la pression en milieu aqueux

Country Status (6)

Country Link
EP (1) EP0418093B1 (fr)
JP (1) JPH03111428A (fr)
KR (1) KR910005975A (fr)
AU (1) AU638736B2 (fr)
DE (1) DE69016325T2 (fr)
MX (1) MX172822B (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0513772A2 (fr) * 1991-05-13 1992-11-19 Norton Company Feuille abrasive
WO1996033842A1 (fr) * 1995-04-25 1996-10-31 Nitta Corporation Toile a polir et procede pour la fixer/detacher a/de la plaque de base d'une polisseuse
EP0747455A1 (fr) * 1995-06-06 1996-12-11 Norton Company Matériau de friction pour supports de film
EP0771613A1 (fr) * 1995-10-31 1997-05-07 Kovax Corporation Feuille abrasive et procédé pour sa fabrication
WO2000012642A1 (fr) * 1998-08-28 2000-03-09 Nitta Corporation Tissu de polissage et procede pour attacher/detacher le tissu de polissage sur/de la plaque de base d'une machine de polissage
WO2000013854A1 (fr) * 1998-09-08 2000-03-16 Struers A/S Support pour fixation temporaire d'une feuille de polissage et/ou d'une feuille abrasive autocollante sur une butee mobile dans un appareil de polissage et/ou abrasion
WO2001053042A1 (fr) * 2000-01-24 2001-07-26 3M Innovative Properties Company Tampon de polissage comprenant une couche de separation
EP1504846A1 (fr) * 2003-08-08 2005-02-09 Procédés et équipements pour les sciences et l'industrie Plateau de polissage comportant un tissu de polissage n'adhérant qu'horizontalement au support
CN110256701A (zh) * 2019-07-16 2019-09-20 海宁三帘纺织有限公司 一种全遮光帘的制作方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20070095601A (ko) * 2006-03-22 2007-10-01 주식회사 디어포스 이중 결합기재를 이용한 연마 제품 및 그 제조방법
CA2849079C (fr) 2011-09-21 2019-06-11 Donaldson Company, Inc. Fibres fines composees de polymere reticule avec une composition d'aldehyde resineux
EP2964817A1 (fr) 2013-03-09 2016-01-13 Donaldson Company, Inc. Fines fibres composées d'additifs réactifs

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB964961A (en) * 1962-09-27 1964-07-29 U K Optical Bausch & Lomb Ltd Improvements in or relating to the grinding of optical lens blanks
US3959935A (en) * 1975-03-18 1976-06-01 Interoptic Laboratories, Inc. Abrasive pad for grinding lenses
FR2418700A1 (fr) * 1978-03-02 1979-09-28 Brueckner Trockentechnik Kg Article pour polir des surfaces a criteres rigoureux
US4240807A (en) * 1976-01-02 1980-12-23 Kimberly-Clark Corporation Substrate having a thermoplastic binder coating for use in fabricating abrasive sheets and abrasive sheets manufactured therewith
US4835217A (en) * 1985-10-17 1989-05-30 Minnesota Mining And Manufacturing Company Pressure-sensitive adhesive having broad useful temperature range

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB964961A (en) * 1962-09-27 1964-07-29 U K Optical Bausch & Lomb Ltd Improvements in or relating to the grinding of optical lens blanks
US3959935A (en) * 1975-03-18 1976-06-01 Interoptic Laboratories, Inc. Abrasive pad for grinding lenses
US4240807A (en) * 1976-01-02 1980-12-23 Kimberly-Clark Corporation Substrate having a thermoplastic binder coating for use in fabricating abrasive sheets and abrasive sheets manufactured therewith
FR2418700A1 (fr) * 1978-03-02 1979-09-28 Brueckner Trockentechnik Kg Article pour polir des surfaces a criteres rigoureux
US4835217A (en) * 1985-10-17 1989-05-30 Minnesota Mining And Manufacturing Company Pressure-sensitive adhesive having broad useful temperature range

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0513772A3 (en) * 1991-05-13 1993-04-14 Norton Company Abrasive sheet material
EP0513772A2 (fr) * 1991-05-13 1992-11-19 Norton Company Feuille abrasive
US6190746B1 (en) 1995-04-25 2001-02-20 Nitta Corp Polishing cloth and a method for attaching/detaching the polishing cloth to/from a base plate of a polishing machine
WO1996033842A1 (fr) * 1995-04-25 1996-10-31 Nitta Corporation Toile a polir et procede pour la fixer/detacher a/de la plaque de base d'une polisseuse
EP0747455A1 (fr) * 1995-06-06 1996-12-11 Norton Company Matériau de friction pour supports de film
EP0771613A1 (fr) * 1995-10-31 1997-05-07 Kovax Corporation Feuille abrasive et procédé pour sa fabrication
AU685030B2 (en) * 1995-10-31 1998-01-08 Kovax Corporation Abrasive sheet and method of manufacturing the same
US5928760A (en) * 1995-10-31 1999-07-27 Kovax Corporation Abrasive sheet with thin resin film
US6616520B1 (en) 1998-08-28 2003-09-09 Nitta Corporation Polishing cloth and method for attaching/detaching the polishing cloth to/from polishing machine base plate
WO2000012642A1 (fr) * 1998-08-28 2000-03-09 Nitta Corporation Tissu de polissage et procede pour attacher/detacher le tissu de polissage sur/de la plaque de base d'une machine de polissage
WO2000013854A1 (fr) * 1998-09-08 2000-03-16 Struers A/S Support pour fixation temporaire d'une feuille de polissage et/ou d'une feuille abrasive autocollante sur une butee mobile dans un appareil de polissage et/ou abrasion
US6607429B1 (en) 1998-09-08 2003-08-19 Struers A/S Support for temporary fixation of self-sticking abrasive and/or polishing sheet
WO2001053042A1 (fr) * 2000-01-24 2001-07-26 3M Innovative Properties Company Tampon de polissage comprenant une couche de separation
US6746311B1 (en) 2000-01-24 2004-06-08 3M Innovative Properties Company Polishing pad with release layer
EP1504846A1 (fr) * 2003-08-08 2005-02-09 Procédés et équipements pour les sciences et l'industrie Plateau de polissage comportant un tissu de polissage n'adhérant qu'horizontalement au support
FR2858574A1 (fr) * 2003-08-08 2005-02-11 Procedes Et Equipements Pour L Plateau de polissage comportant un tissu de polissage n'adherant qu'horizintalement au support
CN110256701A (zh) * 2019-07-16 2019-09-20 海宁三帘纺织有限公司 一种全遮光帘的制作方法

Also Published As

Publication number Publication date
MX172822B (es) 1994-01-14
EP0418093B1 (fr) 1995-01-25
DE69016325T2 (de) 1995-08-10
AU6117090A (en) 1991-03-21
JPH03111428A (ja) 1991-05-13
EP0418093A3 (en) 1992-04-01
KR910005975A (ko) 1991-04-27
AU638736B2 (en) 1993-07-08
DE69016325D1 (de) 1995-03-09

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